The present invention relates to vehicles travelling along a fixed route passing through geographical zones associated with one or several environmental restrictions. In particular, the invention relates to adapting a vehicle control strategy based on the restrictions.
Environmentally sustainable solutions are sought after in numerous fields of technology and industries, particularly in the automotive industry. Even though a lot of progress has been made in the automotive industry with for example hybrid vehicles, electric vehicles, improved fuel efficiency and efficient exhaust gas catalysts there is still incentive and opportunities for further improvements. However, in parallel with automotive development efforts are made by governments and organizations to guide the evolution of vehicles towards more sustainable solutions by penalty taxes, restrictions, etc.
A recent trend, particularly in urban areas, is to provide restrictive areas or zones in which certain requirements are put on the vehicles and indirectly on the drivers, for example low emission zones, low noise zones, reduced speed zones, studless tire zones, etc. A road user operating a vehicle may thus encounter several zones or segments along a route posing various driving requirements or restrictions. The zones or segments may for example be geographical areas, road segments, tunnels, school areas, indoor bus-stops, etc. For example some zones may pose environmental requirements on vehicles traveling in or passing through these zones, such as e.g. low/zero emission zones or low noise zones, and these zones may be of various classes, i.e. the requirements may be stricter in some zones than other. Further, some zones segments may pose safety requirements, such as e.g. speed limitations, axle weight limitation, mandatory stops, right of way, narrow road, dangerous road, pedestrian streets, slippery road, etc. Thus, there may be various driving requirements associated with the aforementioned zones or segments. A safety requirement as mentioned may be a speed limitation, i.e. in some zones adaptation of the vehicle or driving strategy may be to limit the top speed of a vehicle, for example near a school or other places where there are a lot of pedestrians present, or for example near a bus stop for buses.
However, for road users these areas and restrictions may result in additional stress, increased distraction and, as a consequence potential safety hazards. In particular these restrictions often result in stressful situations for road users which are unfamiliar with the local area which may cause them to pose a risk in traffic, but also for professional drivers such as bus drivers already operating under rather stressful conditions.
To this end, attempts have been made to facilitate the situation for road users, such an attempt is e.g. disclosed in EP2153175 which provides a navigation system for a motor vehicle in which information about the geographic location of low emission zones is presented to the driver and, if the vehicle can't comply with the restrictions, the driver is provided with an alternative route.
However, this solution is limited in many ways, and does also not completely solve the problems associated with the increasing number of restrictive zones and the different types of restrictions. For example, it might not always be a viable alternative for a road user to avoid certain areas or zones, and moreover there is still a need for an improved method for adapting a control strategy of the vehicle in order to handle requirements of these zones.
These problems are particularly important for busses or other vehicles travelling along a reoccurring fixed route.
Further attention is drawn to US2012290149, disclosing a computer implemented method includes examining a travel route to determine the presence of emission control zones along the route. The method further includes determining how much power will be required to operate a vehicle along the portions of the route within the emission control zones.
In EP2689982, there is provided a method of determining power source switching for a hybrid electric vehicle, HEV, based on its battery status and pollution information along the planned route.
EP1288887 presents a system and method for providing control grain of a vehicle and, more particularly, to system and method for providing running characteristics of a vehicle which match the preferred drive feel and living environment of a driver by sharing environment data and learned data with a plurality of other drivers.
In US2011246004, there is disclosed a method for determining minimum energy routes for a motor vehicle.
Finally, WO2013055830 relates to a method of charging an energy storage system for an electric vehicle.
It is therefore desirable to provide a method for adopting to restrictive zones or segments in a route, which alleviates all or at least some of the above-discussed drawbacks of the presently known systems.
The invention, according to an aspect thereof, is based on the insight that vehicles travelling along a reoccurring route may have significant use of historical data relating to previous passages along the route, in particular when adapting a vehicle control strategy when considering environmental restrictions, such as emissions, noise, weight, speed, safety, etc.
By collecting historical data from vehicles passing through specific zones or segments of a route, and using this historical data to adopt a vehicle control strategy, it is possible to greatly aid drivers and reduce stress factors associated with driving automotive vehicles.
Further, the usage of historical data will ensure that the predictions become more reliable and that they are more accurate the more vehicles pass through the zone and more data is thus collected.
The term “control strategy” may include any setting of control parameters related to the operation of the vehicle, as well as activities aimed at assisting the driver of the vehicle. In particular, the control strategy may relate to scheduling of battery charging, delaying or expediting particulate regeneration or a change, limitation or scheduling of any other operating parameter. Examples of operating parameters of a vehicle include e.g. speed, engine RPM (revolutions per minute), active gear, heater power, climate system compressor power, onboard media systems, lights/lamps, other onboard subsystems, etc. In case of a hybrid vehicle, an operating parameter may be drive mode, i.e. selecting electric or combustion engine propulsion, or selecting propulsion with different types of fuel or energy sources i.e. gasoline and ethanol.
A reoccurring route may be understood as a route on which the vehicle travels frequently. A reoccurring route offers a greater opportunity for gathering data in which correlations between for example payload and location, speed and time of day or weather and battery discharge rate may be found. Furthermore, the expression “fixed” route is intended to indicate that the route may not be re-routed. A specific case of a reoccurring fixed route is a public transport line, such as a bus route. It occurs several times each day, and may not be re-routed (to any greater extent) as there are predefined bus-stops that need to be frequented. Other examples include some delivery routes, such as a mail delivery route.
When the vehicle is a bus, the step of adapting the vehicle control strategy may include predicting a future delay based on said historical data and updating a time schedule accordingly.
The historical data may include a number of operating parameters. For example, the historical data may include energy consumption for the one or several vehicles that have passed through the zone; it may further include how long time it took to pass through the zone, how many times the vehicle is brought to complete halt, engine load, number of unexpected stops/decelerations, etc. The historical data may further relate to for example vehicle weight, tire pressure, selected gear, activation state of the climate system, interior temperature.
The historical data may be used as a base for predicting or estimating a future state of a vehicle's operating parameters by comparing with similar historical states and how the states develop under similar conditions. The historical data may for example be used to reach or approach a desired state by adapting a vehicle control strategy to settings associated with a desired state or with a development leading to the desired state. The desired state may for example be a successful travel through the zone and/or the historically most energy efficient travel through the zone
According to an aspect of the invention, the historical data is tagged based on at least one parameter, and the method further comprises selecting relevant historical data based on a current or forecasted parameter.
The parameter can be a driving condition, such as traffic density, weather, etc, a geographical position in relation to the zone, a type of vehicle, or any other parameter that can be expected improve selection of relevant historical data. Historical data which is not associated with the current parameter may be disregarded making the method more efficient. Alternatively, the differently tagged data may be weighted to arrive at a suitable vehicle control strategy.
For example if the parameter is “heavy snowfall”, the historical data that was collected during heavy snowfall may then be used when adapting the vehicle control strategy, e.g. with respect to operating parameters such as available torque, etc. Historical data collected during sunny weather may be disregarded, or at least assigned less weight.
In a particular embodiment the tagging parameter is time related, and may be time of year, time of month, weekday, time of day, etc. For example, during certain hours of the day the road might be empty (e.g. late at night), and mainly using historical data showing energy consumption when passing through that zone for that specific time of the day (e.g. late at night) might provide a more accurate estimation of the needed energy level in an onboard energy storage unit if a passage through that specific zone is to be performed solely on electric drive. Consequently, an unnecessary stop to charge the battery/batteries at a charging station may be avoided which will save large amounts of time. Another example may be a zone with an axle-weight restriction during particular hours of the day; if that zone is being approached by a vehicle with an axle-weight above the allowed limit may then be allowed to pass during off-hours and offered an alternative route during hours of prohibition, thus resulting in one less thing for a driver to worry about.
Furthermore, the tagging parameter may be a location relative to the zone. For example, historical data related to a state of charge of a battery at different specific locations along the route may be selected based on the current location. This may also be combined with a time related tag, e.g. a state of charge historically occurring at a specific location along the route on Tuesday mornings between 8 and 9.
The method may further include accessing an onboard information system to acquire current vehicle data.
The current vehicle data is here intended to include any data relating to the vehicle or its immediate surroundings. In other words, it may include internally detectable information (e.g. speed, battery charge) as well as externally detectable information (e.g. outside temperature).
For example, the current vehicle data may be emission data for the vehicle, state of charge (energy level) of one or several onboard energy storage units, engine temperature, cabin temperature, type of tires, noise level, vehicle height data, vehicle axle weight data, fuel consumption rate, vehicle speed, etc. This current vehicle data is then used together with the historical data for the zone that is being approached by the vehicle to adopt the vehicle control strategy, e.g. to ensure compliance with the driving requirement(s) of that zone.
Moreover, current vehicle data may also be data gathered in real-time from vehicles driving the same reoccurring route, e.g. a bus some minutes a head operating in the same bus line. In this way a very accurate prediction can be made if the vehicle will be able to comply with the driving requirements associated with a particular zone. For example, if a bus is driving along a bus route, and approaching a zone with low/zero emission requirements during some divergent public event, e.g. a concert or a sports event, and the buses that have previously passed the forthcoming stop indicate an increasing number of passengers the vehicle may be adapted to compensate for the additional load by allowing a higher state of charge of the onboard energy storage unit so to comply with the low/zero emission requirement associated with the zone that the bus stop is positioned in regardless of the abnormal event.
The method may further comprise the step of collecting data during passage of said zone, and communicating the collected data to the historical data in said database. At the same time as the vehicle makes use of historical data to adopt its vehicle control strategy, data from its passage through the zone may be stored, thereby contributing to the historical data in the database. In this way, the system becomes self-learning, and consistently improves.
In some embodiments, the step of adapting the vehicle control strategy includes adapting at least one operating parameter for optimizing energy consumption of said vehicle. This enables the vehicle to perform in an optimized way in regards to fuel efficiency and energy consumption and not only for compliance with driving requirements set out by zones or segments along the way. The method may also include a specific step of verifying that passage through the zone(s) while complying with environmental restrictions associated with the zone is possible.
For example if the zone that is being approached is a low/zero emission zone and the vehicle is a hybrid electric vehicle with an internal combustion engine and an electrical motor, the vehicle data may be used to determine state of charge (energy level) of the onboard energy storage unit and then to make sure that there is enough charge to allow the vehicle to proceed through the zone solely on electric drive. For example, an adaptation of the vehicle or driving strategy may be then to allow the battery to be charged by powering a generator with the internal combustion engine, and perhaps also turn off the compressor of a climate system in the cabin if it is determined to be necessary in order to ensure compliance with the low/zero emission requirement. Alternatively the vehicle may be directed towards a charging station to charge the onboard energy storage unit before entering the low emission zone. Furthermore, the historical data and vehicle data may be used in combination to make an improved prediction regarding if the vehicle will comply with driving requirements dictated by the zone when passing it.
Moreover, there are many environmental benefits associated with providing more accurate predictions of energy consumption through certain zones or road segments by optimizing fuel efficiency. Additionally a battery in an electric vehicle can be utilized in a way to maximize the life length of the battery. By keeping a charge status within a preferred charge level the battery life is increased. The present invention allows for usage of historical data, which may be real time data from vehicles ahead, vehicles which perhaps passed the zone which is currently being approached only a short while ago, to assess future energy need. Thus, when the battery is being charged, either at a charging station from the electric grid or from an on-board power source, such as e.g. an internal combustion engine, a preferred state of charge can be set so that the vehicle may complete the assignment (e.g. pass through the zone purely on electric drive, in case of an zero emission zone or low noise zone) and minimize the battery wear, simultaneously.
Even further, in another exemplary embodiment the vehicle may have an electric drive mode, and wherein the at least one operating parameter includes activation of regenerative braking. As previously discussed some vehicles, e.g. hybrid electric vehicles may have two driving modes, an electric drive mode or a combustion engine drive mode. Many of these types of vehicles have a regenerative braking feature so to utilize the energy resulting from braking of the vehicle, thus an operating parameter may be to activate this regenerative braking for example if the state of charge in an onboard energy storage unit needs to be increased and the combustion engine cannot generate a high enough state of charge on alone.
In one exemplary embodiment the adapting of operating parameters includes selective deactivation of energy consuming onboard subsystems. Onboard subsystem might be heaters, air condition, infotainment systems, etc. This may for example be used either to ensure the state of charge in a battery and/or to comply with driving requirements in zones with noise restrictions, or if for example a zone is located indoors and the associated requirements with indoor driving e.g. no heater use.
Further, according to one exemplary embodiment, the at least one operating parameter includes scheduling of an onboard electrical energy storage unit by one of a combustion engine and external power source.
Furthermore, the historical data may include payload changes in or along the zone. With reference to public transportation (e.g. buses) “payload” may refer to number of passengers and differences in the number of boarding passengers at one or several stops within a particular zone. The differences may be depending on time of day, weather, public events, etc. This information may be particularly relevant for providing driver assistance. Not only does it affect the weight of the vehicle, but with an increased number of passengers there is an increased risk that one or several passengers are standing up.
In another exemplary embodiment the fixed route extends through at least one additional geographical zone associated with at least one environmental restriction, and wherein said step of adapting said vehicle or driving strategy is based also on a requirement of said additional zone and historical data collected from previous passages of one or several vehicles through said additional zone.
In this scenario the adaption of the vehicle control strategy may consider all or some of the zones along the fixed route. Zones or segments with environmental restriction may be geographically directly connected to one another; however, there may also be intermediate zones without environmental restriction placed in between some or all of the zones with environmental restriction.
By including also restrictions from additional zones along the fixed route, the quality of the driving strategy may be further improved. For example, the state of charge in an onboard energy storage unit must be sufficient not only to comply with a possible first low/zero emission zone, but also in the case where there is another low/zero emission zone close by. In particular if there would not be possible or optimal to charge the battery between the two low/zero emission zones.
According to a second aspect of the present invention, an on-board system for adapting a vehicle control strategy of an on-road vehicle is provided.
Advantages and variations are in large similar to those discussed above with respect to the first aspect of the invention. For example, the control unit may be configured to select relevant historical data based on a current or forecasted condition, and/or configured to access an information system, and/or configured to communicate current vehicle data and/or the determined position to the database, and/or configured to receive current vehicle data from another vehicle travelling along the fixed route, and/or configured to predict a future delay based on said historical data and updating a time schedule accordingly.
A further aspect of the invention relates to a plurality of vehicles each comprising a system according to the second aspect of the invention, wherein the vehicles travel along a common fixed route at separate incremental positions, and wherein vehicle data of a preceding vehicle of the plurality of vehicles is comprised in the historical data for access by a following vehicle of the plurality of vehicles.
These and other features and advantages of the present invention will in the following be further clarified with reference to the embodiments described hereinafter.
All the figures are highly schematic, not necessarily to scale, and they only show parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.